Former US President Bill Clinton is one of the high profile supporters of the Business Backs Education campaignReuters

Some of the world's largest companies only spend "a fraction" of their corporate social responsibility (CSR) on education, according to the Varkey Foundation.

The research commissioned as part of the Business Backs Education campaign found that global Fortune 500 businesses only spend $2.6bn (13%) of their $19.9bn CSR budgets on education related activities.

The study also revealed that that less than half (218 companies) of the Fortune 500 provide any spending on education-related CSR.

The Business Backs Education campaign challenges business to commit 20% of their global CSR spend on education by 2020 and is supported by former US President Bill Clinton and the Mayor of London Boris Johnson.

"This is designed to bring business in line with Government spending targets," the organisation said.

"Unesco recommend that Governments should spend 20% of their budget on education and that 20% of Official Development Assistance should go towards education initiatives.

"This is of particular importance as the gap between education demand and provision rises, particularly in developing countries, and there is a recognition that government on its own cannot plug this gap."

The report explained US companies form the largest proportion of the Fortune Global 500 and thus spend the most on CSR and education CSR, with IBM, Exxon Mobil, Target, Microsoft and Wells Fargo the top five US companies.

The 132 US Fortune Global 500 companies spent US$10,254m on CSR activities and 10% of this, or US$1,065m, on education-related activities (as an average of the three years 2011 – 2013).

The Varkey Foundation said the findings provide "strong evidence" that corporate giving to education is considerably below spending on other areas such as health.